Do you know how to make a Chicago federal judge steaming mad? City Hall lawyers do. Again and again, they’ve been reprimanded for messing with the integrity of police misconduct cases by withholding evidence.

This lack of respect for the discovery system sure gets the goat of judges. Or as U.S. District Judge Rebecca Pallmeyer put it: “I am really dismayed.”

Citizens, you should be dismayed, too, because these foul-ups cost taxpayers money in fines, settlements and reforms. Since Mayor Rahm Emanuel took office in 2011, federal judges have sanctioned the city’s Law Department nine times for failing to turn over evidence to plaintiff attorneys, racking up more than $1.1 million in fines. Nine times? It’s almost as if the city doesn’t want to air damaging information about police conduct.

Oh, did we say nine times? On Thursday, the city was going for 10. Pallmeyer was set to hold a sanctions hearing over the Law Department’s mishandling of the Jaquise Evans case until the city caved and reached a settlement. Another pricey black eye.

Here’s what happened: In 2015, Chicago police Sgt. Richard Salvador shot and wounded Evans, 16, who filed a civil rights lawsuit against the city. Under pretrial rules of discovery, city attorneys should have shared important background information on Salvador with Evans’ attorneys in a timely manner. Instead, the city’s Law Department revealed just before the scheduled start of the trial that there were several citizen complaints against Salvador. Plus, there was a Facebook video of the officer screaming at and threatening violence against a handcuffed African-American arrestee.

The two sides disagreed about the timing of notification of the video, but this month Pallmeyer chastised city attorneys for not being more concerned by its disturbing content. “To call what happened on that video nothing more than use of profanity is just — nobody in this room believes that,” she said according to a transcript. “Did that trouble you at all?” she asked.

It got worse for the city when Pallmeyer learned Salvador had been named in another civil rights lawsuit. What’s more, Salvador’s attorney in the case, Assistant Corporation Counsel Scott Cohen, also represented him in the other suit, yet the second suit wasn’t shared with Evans’ attorneys. When Cohen explained that he hadn’t realized he was representing the same officer, Pallmeyer was livid: “I’m sorry, as a matter of professional responsibility, you don’t know who your client is? What law firm, what city, what anything allows you to say, ‘I don’t remember that I was his lawyer?’ ” The judge couldn’t believe city attorneys didn’t keep a running list of clients. “Who dropped the ball?”

Excellent question but not unique. Last month, in a different police misconduct case, U.S. District Judge Virginia Kendall also was stunned by a late-breaking revelation. During a wrongful-death trial, former Detective Joseph Frugoli, who killed two men in a DUI crash, revealed he’d been suspended in 2002 for a bar fight. City attorneys said that paperwork had been overlooked. Turns out he had attacked customers, hit someone over the head with a pool cue and shouted, “Nobody messes with the Frugolis!” He was suspended for just five days.

That’s the kind of evidence plaintiffs’ attorneys would crave because it went to the heart of their allegations that the police protect their own. “This is highly damaging information,” Kendall said. Not surprisingly, the city quickly settled the case for a reported $20 million.

Now we’ve got another settlement, and an acknowledgment Thursday from the Law Department that it is examining its discovery practices “to identify improvements.”

Given the city’s dismal performance record in court and failed attempts at reform, that statement is woefully inadequate. In 2016, the city paid big bucks to former prosecutor Dan Webb to scrub the Law Department’s civil rights litigation practices. He found no evidence of intentional misconduct but laid out dozens of recommended improvements to the way discovery, record-keeping and other practices are handled. A lot of good Webb’s advice did.

How many more cases will Emanuel’s lawyers screw up before they fix the way they defend police misconduct cases?